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A163509 Take n written in binary. Replace the leftmost run of 1's with just a single 1. a(n) is the decimal equivalent of the result. 1
1, 2, 1, 4, 5, 2, 1, 8, 9, 10, 11, 4, 5, 2, 1, 16, 17, 18, 19, 20, 21, 22, 23, 8, 9, 10, 11, 4, 5, 2, 1, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 16, 17, 18, 19, 20, 21, 22, 23, 8, 9, 10, 11, 4, 5, 2, 1, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
EXAMPLE
29 in binary is 11101. Replace the three 1's on the left of the binary representation with one 1, getting 101. a(29) is the decimal equivalent of the result, which is 5.
MAPLE
A163509 := proc(n) bdgs := convert(n, base, 2) ; while op(-1, bdgs) = op(-2, bdgs) do bdgs := subsop(-1=NULL, bdgs) ; od: add( op(d, bdgs)*2^(d-1), d=1..nops(bdgs) ) ; end: seq(A163509(n), n=1..120) ; # R. J. Mathar, Aug 07 2009
MATHEMATICA
Table[FromDigits[Flatten[Join[{1}, Rest[Split[IntegerDigits[n, 2]]]]], 2], {n, 80}] (* Harvey P. Dale, Jul 17 2014 *)
CROSSREFS
Sequence in context: A371015 A090077 A229763 * A161399 A318479 A053985
KEYWORD
base,look,nonn
AUTHOR
Leroy Quet, Jul 29 2009
EXTENSIONS
More terms from R. J. Mathar, Aug 07 2009
STATUS
approved

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Last modified July 15 10:20 EDT 2024. Contains 374329 sequences. (Running on oeis4.)